Visualization of Ovarian Tumors using 3T MR Imaging: Diagnostic Effectiveness and Difficulties

Abstract

Purpose: We evaluated the diagnostic eŠectiveness of magnetic resonance (MR) imaging at 3 tesla to visualize ovarian tumors and problems associated with its use.Materials and Methods: From the records of 423 consecutive women who underwent pelvic MR imaging using a 3T system from April 2009 to June 2010, we analyzed 50 continuous cases of ovarian tumors proved by histopathology. We evaluated visualization of these tumors for image quality and artifacts using 5-point scales. For qualitative assessment, we scored overall image quality (1, poor, to 5, excellent), degree of conviction regarding the diagnosis (1, undiagnosable, to 5, diagnosable with high certainty), and 4 representative artifacts (penetrating, chemical shift, motion, and susceptibility artifact) (1, severe, to 5, little degradation). We also retrospectively reviewed the diagnostic features of the ovarian tumors and preoperative diagnostic accuracy. For quantitative assessment, we determined tumor size and ADC value.Results: Overall quality score was scored 4.9±0.5, and conviction regarding diagnosis was 4.9±0.3. Artifacts caused little degradation in most cases: penetrating, 4.8±0.5; chemical shift, 4.3±0.5; motion, 4.6±0.6; and susceptibility, 3.8±0.9. Preoperative diagnostic accuracy was 92z (sensitivity 94.7z, speciˆcity 90.3z). Mean tumor diameter was 88.3±61 mm. The mean ADC value was 1.04±0.3 in malignant tumors and 1.15±0.5 (×10 -6 mm 2 /s) in benign tumors.Conclusion: The quality of ovarian tumor images obtained with a 3T MR imaging system is adequate for diagnosis, with only slight degradation from penetrating or susceptibility artifacts.

Apparent diffusion coefficient (ADC) measurement in ovarian tumor: Effect of region‐of‐interest methods on ADC values and diagnostic ability

“…These findings may cause penetration artifacts. 6 In addition, susceptibility artifacts may influence the ADC measurement because ovarian tumors often tend to be massive intrapelvic-abdominal pathologies closer to the rectum and small intestine. A previous report showed that these artifacts are not a major problem in diagnosing ovarian tumors and in differentiating between benign and malignant ovarian tumors.…”

“…A previous report showed that these artifacts are not a major problem in diagnosing ovarian tumors and in differentiating between benign and malignant ovarian tumors. 6 However, it is difficult to avoid all artifacts, particularly in drawing freehand ROI. The present results demonstrate that all ADCs have significant differences between benign and malignant tumors.…”

“…Magnetic resonance imaging (MRI) plays an important role in the diagnosis of ovarian lesions. [1][2][3][4][5][6] MRI can reveal morphologic characteristics and signal intensity of tumor. Diffusion-weighted imaging (DWI) has been widely accepted as a useful imaging technique to detect and characterize focal lesions in many regions of the body including pelvis.…”

A new phantom and empirical formula for apparent diffusion coefficient measurement by a 3 Tesla magnetic resonance imaging scanner

“…Recently, popularized 3 Tesla (3T) MRI devices have shown a performance advantage when calculating accurate ADC values. Several clinical studies have revealed that ADC values from 3T MRI have the diagnostic value as a quantitative parameter (1–8). However, to the best of our knowledge, there are no reports of an ADC phantom for 3T MRI.…”

Management of epithelial ovarian cancer from diagnosis to restaging

“…The use of contrast media may also improve the overall accuracy, although some benign lesions may show a malignant-like appearance, leading to false-positive results [28][29][30][31]. The use of 3T MRI does not seem to significantly improve the ability of MRI, showing a diagnostic accuracy of 92%, a sensitivity of 94.7% and a specificity of 90.3%, [32].…”